Still no photos of the engine on the web so I thought to amend that.
Now I understand why there aren´t any.
THE CASE BACK IS WIS RESISTANT!
Mine has grown quite a bit of sabi, being worn daily on the farm so I did not pussyfoot about.
I even put on gloves to use a serious knife but NO WAY.
The fit is só good that no hand tool can be wedged anywhere.
There is just no way to get it off without a special vice.
So, sorry, no photos from me either